There are several laundromats in my small town and they seem to be always busy. They are clean and each have a person to oversee things. They are both open 7 days a week One opens early and one stays open until 10. I think they are both owned by the same person. It was sure handy to have when my area lost power for a couple of weeks. I was shocked at the price per load the last time I was there. LOL My daughter when in high school use to take all her laundry to one, wash and dry all at once to get it over with.
How I wash any big quilt is put in my washer with a little detergent (top loader) and turn the washer off when filled. Let soak for a little then select drain. Repeat with clean water then select drain and spin. Then I put the whole thing in the dryer. I don't agitate or swish it as my washer does.